The present invention relates to a control switch apparatus capable of setting operation of the control switch in an “enabled” or “disabled” state and relates to a detent changeover switch capable of switching a click feeling developing in an operating portion of a control switch.
A vehicle has hitherto been equipped with a variety of control switches that are operated at the time of activation of various vehicle-mounted devices, such as an air conditioner, audio equipment, and a car navigation system. Often used as the control switch of this type is a rotary switch that enables selection and designation of various operating functions, such as switching power of a vehicle-mounted device between an ON position and an OFF position, selection of a functional item, and operation pertaining to an amount of operational control, by means of rotation of a dial knob serving as an element to be operated. An example of such a rotary switch is described in JP-A-2004-220957. A rotary switch for use in an air conditioner includes; for example, a temperature setting switch for setting the temperature of an air blast, an air flow rate setting switch for setting the volume of air blow, and a wind direction setting switch for setting the direction of a wind.
Incidentally, in many cases, a rotary switch of an air conditioner is a switch having a limited range of rotational operation where a dial knob is operated within a predetermined rotational control range in order to make temperature setting and selection function setting. Therefore, the rotary switch of this type has a rotation stop mechanism for limiting rotational operation of the dial knob at a predetermined position. According to applications, a rotary switch having a rotational operation range of 120°, a rotary switch having a rotational operation range of 180°, and a rotary switch having a rotational operation range of 270° are prepared. An example rotation stop mechanism has a dial knob, a case for rotatably supporting the dial knob, an engagement portion provided on either the knob or the case, and a portion to be engaged with the engagement portion (an “engaged portion”) provided on a remaining element. When the engagement portion contacts the engaged portion during rotation of the dial knob, further rotation of the dial knob is restricted, thereby restricting the range of rotational operation.
However, the rotation stop mechanism described in connection with the background art has a structure in which the engagement portion is provided one of the dial knob and the case and the engaged portion is provided on the remaining element. Hence, both the dial knob and the case must be subjected to machining for implementing a rotation stop mechanism. When a rotary switch is manufactured, both the dial knob and the case require machining processes, and hence there arises a necessity for preparing a product whose dial knob and case differ in shape from their conventional counterparts. For this reason, there exists a desire for using hitherto-used components as intactly as possible by means of reducing the number of required machining processes for machining the rotation stop mechanism.
On the other hand, in order to enhance an operation feel of a dial knob and make operation of the dial knob reliable, the rotary switch of this type is provided with a detent mechanism that imparts desired operating force or a tactile feel to the dial knob as a click feeling. In a common detent mechanism, a plurality of detent crests are provided along the direction of rotation of the knob on either a dial knob to be rotationally operated by an operator or a case supporting the dial knob in a rotatable manner. A detent piece that is urged against the detent crests at all times by means of an urging spring is provided on a remaining one of the dial knob and the case. Operating force developing when the detent piece gets over the detent crest as a result of the dial knob being rotationally operated by the operator is imparted as a click feeling to the operator.
Incidentally, in order to curtail the number of components of the control switch, an attempt has recently been made to share one rotary switch among a plurality of selective functions. In the case of the shared structure of the control switch of this type, when a switch determination mode enters a function selection setting mode in a switch determination initial state and when the dial knob is operated at this time, a switch controller serving as a control unit of an input operation system selects and designates vehicle-mounted equipment for which the operator desires to set a function at that time, by use of a switch signal acquired from a rotary switch. The switch controller switches the switch determination mode to a detailed setting mode after selection and designation of the vehicle-mounted equipment. When the dial knob is operated, details about the vehicle-mounted equipment selected and designated at that time are set to a state conforming to switching operation, by use of the switch signal acquired from the rotary switch at that time.
In the case of the shared structure of the control switch, the click feeling caused in the rotary switch by the detent mechanism desirably changes according to selective functions. Patent Document 1 describes; for example, a detent changeover technique of switching a click feeling from one selective function to another by means of the shared structure of the control switch of this type. The technique described in Patent Document 1 is for vertically positioning a plurality of discs whose detent crests are spaced at different pitches; vertically moving the detent piece by means of an actuator so as to selectively bring the detent piece into elastic contact with one detent crest of one of the discs, thereby switching a click feeling acquired at the time of rotational operation of the dial knob.
According to the technique described in JP-A-2002-189559, when one rotary switch is shared among a plurality of selection functions, the click feeling developing in the dial knob can be switched from one selection function to another. However, since each click feeling to be generated requires a disc, discs equal in number to all of the click feelings to be generated are required. Therefore, as the number of click feelings to be developed in one rotary switch increases, the number of required discs is increased correspondingly. Hence, the number of discs provided in the control switch apparatus becomes greater, which in turn leads to a fear of an increase in the size of the control switch apparatus. Moreover, when the number of components of discs increases, component costs are correspondingly incurred in the discs, and there is a fear of this leading to an increase in the component costs.